JP4915907B2 - IPM-mounted solar inverter and its manufacturing method - Google Patents

Description

  The present invention relates to a structure of a solar inverter, and more particularly to a solar inverter that can be provided with high reliability with a structure that facilitates installation wiring work and a method for manufacturing the same.

Conventionally, solar battery modules connected in series with solar cells are connected in series to obtain the desired voltage, and the construction time is reduced by reducing the number of man-hours at the installation site of the solar inverter that converts this direct current to alternating current. In addition, the realization of a simple photovoltaic power generation system capable of ensuring reliability was desired.
Patent Document 1 (paragraph 0003) has the following description. “Conventional photovoltaic power generation systems have many components, requiring time and labor to install, and in the case of a small capacity system, there is a problem that the cost is high. It needs to be replaced. For this reason, there is a problem that expansion is not easy. "

For this reason, a light and small inverter has been craved. Regarding IPM (intelligent power module) technology, which is a fundamental technology for realizing a small inverter, there is Patent Document 2 that discloses a technology related to a conventional “intelligent power module”.
When FIG. 1 of Patent Document 2 is shown in this specification as FIG. 8 as it is without changing the symbols of the respective parts, it will be described in (paragraph 0006) as follows. The thickness of the metal film provided on the ceramic plate is very thick, about 300 to 500 μm, and it was difficult to make the wiring fine when the circuit wiring of the control unit was formed with the metal film. The power device chip of the inverter part and the control part were mounted on the metal plate.

Patent Document 2 (paragraph 0013) has the following description as the contents of the invention. “In the intelligent power module of this embodiment, the ceramic plate 4 formed with a metal film 3 made of copper for wiring with a thickness of 300 to 500 μm on the back surface is provided in the target area on the metal plate 1 made of copper plate. A metal film 5 made of a copper material is partially formed in a target region on the ceramic plate 4 with a thickness of 300 to 500 μm, which is fixed by a low-temperature solder 2 such as crystal solder, etc. The metal films 3 and 5 are fine. “The ceramic plate 4 is formed with a thickness of 600 μm because it is not intended for wiring but is intended for dealing with a large current and is formed.” Further, “The ceramic plate 4 is formed with a thickness of 600 μm. Device chips 7a and 7b are joined by high-temperature solder 6. Power device chips 7a and 7b and other metal film 5 are connected by a thin metal wire 9 made of aluminum. Mounting to power device chip 7a, by 7b, the inverter unit 10 is formed. "There are described.
According to (paragraph 0017), “in this embodiment, the region where the ceramic plate 4 is formed is a half region, but the region is adjusted by the size, number, etc. of the power device chips 7a, 7b. In addition, the metal films 3 and 5 made of copper material for wiring are bonded to the ceramic plate 4 with an epoxy adhesive, and the thin metal wires 9 are not limited to aluminum wires. It can also be applied to gold wires. "
(Paragraph 0019) states that “the inverter 10 region of the intelligent power module of the present embodiment is formed with the thick metal films 3 and 5 using the ceramic plate 4, and thus operates with a large current of 100 A or more. However, it is described that the area of the control unit 11 can be reduced because the metal film is finely wired on the resin substrate 14.
As described above, in the inverter unit 10, the ceramic plate 4 is fixed to a target region on the metal plate 1, and the metal film 5 is formed in the region on the ceramic plate 4 with a thickness of 300 to 500 μm. If the power device chip is mounted on the inverter and the current in the inverter section is 10 ampere, the power device chip generates a large amount of heat, which adversely affects the device 8 of the control section 11 and lacks reliability. There was a concern. The ceramic plate 4 is very thick as 600 μm, and it has been desired to reduce the thermal resistance.

Japanese Patent Laid-Open No. 9-201061. “Title of Invention: Solar Power Generation System” Japanese Patent Laid-Open No. 7-86497. “Title of Invention: Intelligent Power Module”

  The conventional solar power generation system described in Japanese Patent Application Laid-Open No. 9-201061 has a large number of constituent devices, which is troublesome to install, and in the case of a small capacity system, there is a problem that the cost is increased. Moreover, when adding a solar cell module, when the output total of a solar cell module becomes larger than an inverter output, it is necessary to expand an inverter or to replace | exchange an inverter with a big output. For this reason, there was a problem that the solar cell module could not be easily increased with the conventional configuration.

  It is important to be able to manufacture in a process that eliminates the elements of reliability and ensures quality. For this reason, it is possible to realize a product structure that can be set to a “process delimiter” that can check the quality between manufacturing processes, and to provide an inverter with a compact product and a structure that is easy to install and connect. It was a problem to make the structure possible.

  With respect to claim 1, in order to solve the above-mentioned problem, a product structure is realized in which a “process delimiter” capable of quality check between manufacturing processes can be set, and a lead wire terminal zone, An insulating box frame body in which the power module (IPM) zone is partitioned by a partition wall is formed, and a manufacturing method in which completeness can be checked by a characteristic test for each partition of the manufacturing process.

  The step of providing input / output connection means on the heat sink, the step of fixing the power semiconductor element to the heat sink, the heat sink on which the terminal connection means is formed is fixed to the electrically insulating box frame with an insulation interval. A step of forming a frame having a heat sink attached by insert molding, a step of connecting between semiconductor element elements, a step of filling a zone of the heat sink with an insulator to complete product intermediate A, the product intermediate A step of performing a characteristic test of A, a step of fixing the product intermediate A to a solar cell module panel, connecting a solar cell module output lead wire to a terminal connection means in a module lead wire terminal zone of the heat sink, After performing a performance test at the stage of this product intermediate B, it is provided with a step of filling an insulating material so as to cover the connection part. And the manufacturing method of chromatography data.

  With respect to claim 2, the heat sink having the input / output terminal connection means, to which the power semiconductor element is fixed, is fixed to the insulating box frame with an insulation interval, and the heat sink and the conductive plate are made of metal conductors. A power module IPM is formed by the insulating box frame that is connected and filled with the insulator and the heat radiating plate, and is fixed to the solar cell module panel, and the solar cell module lead wire is connected to the terminal connection means. A solar inverter equipped with an IPM equipped with an input / output terminal is characterized in that an insulating material is filled in a part covering the part.

  With respect to claim 3, the power module (IPM) is composed of a heat radiating plate to which a power semiconductor element is fixed and a control unit formed of a multilayer printed wiring board or a control IC, and an insulating box frame. The power module (IPM) has a structure in which the power element is directly fixed to the heat radiating plate without using an insulator, and the heat radiating plate in the power module (IPM) zone is fixed or insert-molded while maintaining an insulation interval. 3. The input / output terminal according to claim 2, wherein the power semiconductor element is directly fixed to the heat radiating plate without using a ceramic insulating plate to improve thermal resistance. A solar inverter equipped with an IPM.

  According to claim 4, the solar cell module panel has an IPM-mounted solar inverter with input / output terminals according to claims 2 to 3, wherein the solar cell module panel is fixed to a substantially central portion of the solar cell module panel via a heat conductive thin insulating plate. .

  According to a fifth aspect of the present invention, there is provided an IPM-mounted solar inverter with input / output terminals according to the second to fourth aspects, wherein the terminal connecting means is a receptacle terminal formed so that the lead wire can be soldered.

  With respect to claim 6, the terminal connecting means formed in the vicinity of the end portion of the heat sink is a receptacle terminal having a terminal structure that can be inserted and connected. did.

  The inverter mounted with IPM is fixed to the solar cell module panel, and the solar cell module panel acts as a heat radiating fin of the power semiconductor element, so that the temperature rise value of the power semiconductor element is suppressed and the reliability of the IPM is improved. The structure is easy to check for quality at the intermediate product stage. Since the cable connection work to the external connection terminal at the time of installation has become easy, the work completeness is improved, the overall product completeness is increased, and the installation work cost is significantly reduced.

  An embodiment according to the present invention will be described with reference to FIG. FIG. 1 is an explanatory diagram for associating a circuit with a circuit according to one embodiment, and FIG. 2 is a plan view for explaining a structure according to one embodiment. This will be described with reference to FIGS. The insulating box frame 17 is formed of an insulator such as epoxy resin, and the solar cell module lead terminal zone DC1 is a third heat sink zone in which the power semiconductor elements Q1 and Q2 are fixed on the collector electrodes C1 and C2 side. 29 is located at the same place. The positive electrode terminal zone 29 for solar cell output cable and each zone are divided by the partition wall 12 to form the terminal connection means T3. For example, the heat radiation plates AC1, AC2 and the heat radiation plate DC1, which are copper plates having a thickness of 3 mm, are insert-molded. Or it adheres to this partition 12 with an adhesive agent. The heat radiating plate and the conductive plate DC2 are attached with an insulation interval 20 of about 2 mm, and the collector electrode C3 of the power semiconductor element Q3 is soldered to a substantially central portion of the first heat radiating plate AC1, so that the power semiconductor element Q1 is Q3 is electrically connected in series, and this connection point is connected to the inverter output terminal T1. Product intermediates with power semiconductor element heatsink zones 27, 28 and 29 and negative conductive plate zone 30 filled with insulators such as silicon rubber and epoxy resin are quality and reliable in electrical property tests and temperature / humidity environment tests. Sex is confirmed. It becomes a product intermediate and becomes a break of the manufacturing process.

  FIG. 3 is a cross-sectional view taken along the line CC in FIG. 2 according to an embodiment of the present invention. The collector electrodes C1 and C2 of the power semiconductor elements Q1 and Q2 are fixed to the heat sink DC1 with high-temperature solder, and Q1 and Q2 are electrically connected. Has been. Here, the terminal connection means T3 formed on the heat sink DC1 is a receptable terminal to which the terminal can be inserted and connected for a small current of 5 amperes or less. When it is desired to make it extremely small, it is effective to use a screw terminal block (T3, T4 in FIG. 3) having a screw hole structure in which the crimp terminal of the input / output cable can be screwed. In mass production, it is preferable to use a sheet metal terminal for soldering. The collector electrode C4 of the power semiconductor element Q4 is soldered to a substantially central portion of the second heat radiation plate AC2, and the power semiconductor elements Q2 and Q4 are electrically connected in series, and this connection point is connected to the inverter output terminal T2.

  The power semiconductor switching element generates heat during energization, but the bottom 21 (C-C cross-sectional view) of the heatsink zones 27, 28, 29 is (at least a heatsink) so as to keep the temperature rise value low to improve reliability. The thickness is reduced so that the thermal resistance is small (for example, the portion where DC1 is in contact), for example, a thin plate portion is formed to be 1 mm or less, or the bottom portion 21 where the heat sinks DC1 and AC1 are in contact is formed. The thermal conductive insulating sheet (thermal sheet) with excellent thermal conductivity is bonded to the heat radiating plates DC1, AC1, and the negative conductive plate DC2 to prevent water intrusion and at the center of the back of the solar cell module panel. Since such a large heat conduction means is secured, it is cheaper and has a lower thermal resistance than the conventional case where the power semiconductor is fixed via ceramic.

  A manufacturing method of an embodiment according to the present invention will be described with reference to a process diagram shown in FIG. Terminal connection means for the first heat sink AC1 (AC lead wire terminal zone), the second heat sink AC2 (AC lead wire terminal zone), the third heat sink DC1 (DC lead wire positive terminal zone heat sink), and the conductive plate DC2, respectively. Step 3 for providing T3, T4, T1, and T2, and then Step 2 for fixing the collector electrode of the power semiconductor element to each heat sink by high-temperature soldering Step 2 The emitter electrode of the power semiconductor element is each heat sink (or conductive plate DC2) Step 3 to be connected to each other by solder, Step 4 to form an insulating box frame 17 in which each heat radiating plate and conductive plate DC2 are fixed by an adhesive or the like, Step 4, a heat radiating plate to which the semiconductor elements of the frame 17 are soldered Step 5 for filling the zones 27, 28, 29 and the conductive plate zone 30 with an insulating material such as epoxy resin Step 5, through the above steps Product intermediate A is completed.

  Since the product intermediate A as described above is in a state where a reliability test such as humidity resistance and vibration resistance can be performed, “separation into processes” can be set here. Through the product intermediate property test step Step 6, it can be assured that the product can withstand a long-term change in temperature resistance and moisture resistance.

  Next, after fixing the above product intermediate to the back or side of the solar cell panel by bonding or screwing, the solar cell module lead wires are connected to the terminal connection means T3, T4 of the terminal zones 22, 23. Then, after the characteristic test (of the product intermediate B), the connection portion is filled with a moisture-proof insulator.

  An inverter output cable is connected to the terminal connection means T1 and T2 of the AC terminal zones 27 and 28, and a moisture-proof insulator is filled in the connection portion through a characteristic test (product intermediate B).

  In this way, every time a product intermediate is obtained, process delimiters are provided and quality can be confirmed in the test process. Therefore, there is no process loss compared to the conventional method in which the test result is poor in the final process. Cost is low.

  FIG. 4 is an explanatory diagram of a terminal drawing method and a heat sink, DC1, AC1, and AC2 insulation arrangement according to an embodiment of the present invention. The power semiconductor shown in FIG. The elements Q1, Q2, Q3, and Q4 are shown separately as C1, C2 on the collector side and E3, E4 on the emitter side, respectively. It is also effective to fix the receptacle terminal in the vicinity of the front end portion of the heat radiating plates AC1, AC2, DC1 and the conductive plate DC2 or to form the terminal connection means T1, T2, T3, T4 by drilling the vicinity of the front end portion.

  In the case of FIGS. 5 and 6 which are structural diagrams of the second embodiment, the terminal shape of the terminals T1 to T4 is a screw hole type terminal in the vicinity of the end where the heat sink is bent as shown in the figure. Since a space is formed below the projection of the terminal portion, there is an advantage that a space for providing the control unit 11 can be secured here. When the control unit 11 is connected to the control poles G1 and G3 of the power semiconductor element by the thin metal wire 9, the wiring can be shortened and radiation interference can be reduced. A suitable space for arranging the control unit 11 such as the control IC is a space below the projection of the terminal portion.

  5 and 6 are structural diagrams for explaining the second embodiment according to the present invention. The insulating box frame 17 is formed of an insulating material such as an epoxy resin, and the positive electrode terminal connecting means T3 of the solar cell module lead wire is bent by extending the third heat radiating plate upward and further bent at a substantially right angle to be a horizontal plane. The positive terminal T3 is provided at this site. The lower projection surface of the positive terminal T3 is a third heat radiating plate to which the power semiconductor elements Q1 and Q2 are fixed. However, since a space is formed, the control unit 11 is formed in this portion with a multilayer substrate with a small occupation area. For example, the collector electrode of power semiconductor elements Q1, Q2, Q3, and Q4 is soldered to a substantially central portion of the heat radiating plates DC1, AC1, and AC2 that are copper plates having a thickness of 3 mm, and 40 mm × 30 mm in the vicinity where the power semiconductor is mounted. A control unit 11 formed by arranging fine components in a layer of a multilayer printed wiring board to the extent is mounted via an insulating layer, and the control electrodes (gate electrodes) of the semiconductor elements Q1, Q2, Q3, Q4 and the control unit 11 The drive pulse output terminal is connected by a thin metal wire 9. A circuit for controlling the drive pulse output signal and an inverter abnormality detection control circuit can be mounted on a multilayer printed wiring board having a bottom area of about 40 mm × 30 mm. A bridge circuit of a power semiconductor element incorporating the control unit 11 is mounted on the heat sinks DC1, AC1, and AC2 to form an inverter IPM, and an alternating current with an inverter output current of about 10A can be extracted from the solar cell module from the terminal means T1 and T2. Since the effective space on the lower surface of the panel of the solar cell module can be used as the inverter installation location, it is possible to reduce the total cost of equipment and construction costs when it is difficult to secure the installation space for the conventional installation type inverter. Effective for equipment. It is also effective to use the control IC as the control unit 11.

  FIG. 6 is a structural diagram for explaining the second embodiment of the present invention. The insulating box frame 17 is formed of an insulator, and the positive electrode terminal connecting means T3 of the solar cell module lead wire is bent by extending the third heat radiating plate upward and further bent substantially at a right angle to extend to the horizontal plane. A positive terminal T3 is provided. The negative electrode side terminal T4 was formed as a terminal T4 having a screw hole terminal provided on a horizontal plane obtained by bending the negative side conductive plate DC2 connected from the emitter side with the metal conducting band 13a upward and further bending at a substantially right angle. The control unit 11 is mounted on the upper surface of the negative conductive plate DC2, and the control unit is wired to the control poles G3 and G4 of the power semiconductor elements Q3 and Q4 with a thin metal wire. The inverter part 10 was formed by connecting the emitters of the power semiconductor elements Q1 and Q2 and the heatsinks AC1 and AC2 with the power semiconductor elements Q3 and Q4 fixed on the collector side by metal conductive bands 13b and 13c, respectively. Since the heat sinks DC1 and AC1 and AC2 are insulated from each other by the partition wall 12, power semiconductor elements can be directly attached to the heat sinks, and the effect of drastically reducing the thermal resistance is obtained. The expensive member and process which attach a metal film on both surfaces of the 600-micrometer-thick ceramic board of FIG. 8 became unnecessary.

  The product intermediate in which the heat sink zones 27, 28, 29, and 30 of the inverter IPM in Fig. 2 are filled with an insulator such as silicon rubber or epoxy resin has been confirmed for quality and reliability through electrical property tests and temperature / humidity environment tests. Is done. It becomes the product intermediate A in the process diagram step 5 of FIG. It is also effective to provide a through-hole having a size capable of introducing a lead wire of a solar cell module and a cable for external wiring at the bottom 21 of the terminal zone 22 in FIG.

  Realized with a product structure that can set a “process separation” that allows quality checks between manufacturing processes, ensuring high reliability with a structure that facilitates installation and wiring work, and providing it at low cost As a result, the expansion of solar cell modules has become easier, and the contribution to the industry is high.

FIG. 1 is an explanatory diagram of a circuit and structure association according to an embodiment of the present invention. Structure diagram of one embodiment according to the present invention Sectional view of one embodiment according to the present invention Terminal drawing explanatory drawing of one embodiment by the present invention Structure diagram of second embodiment according to the present invention Structure diagram of second embodiment according to the present invention Process drawing of one Embodiment by this invention Structure of conventional inverter IPM

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal plate 2 Low temperature solder 3 Metal film 4 Ceramic plate 5 Metal film 6 High temperature solder 7a, 7b Power semiconductor (switching) element 8a, 8b Control device 9 Metal thin wire 10 Inverter part 11 Control part 12 Bulkheads 13, 13a, 13b 13c , 13d Metal conductive band 14 Resin substrate 16 External connection terminal 17 Insulating box frame 18 First filling insulator 19 Second filling insulator 20 Insulation interval 21 Bottom 22, 23 Terminal zone 27 First heat radiation zone (AC terminal zone)
28 Second heat sink zone (AC terminal zone)
29 Third heat sink zone (positive terminal zone)
30 Negative conductive plate zone (negative terminal zone)
AC1 1st heat sink AC2 2nd heat sink DC1 3rd heat sink DC2 Negative side conductive plate T1 Terminal connection means (inverter output, AC side)
T2 terminal connection means (inverter output, AC side)
T3 terminal connection means (solar panel output, DC positive side)
T4 terminal connection means (solar panel output, DC negative side)
C1 to C4 Power semiconductor (switching) element collectors G1 to G4 Signal terminals (terminals for control leads)
P Control devices Q1-Q4 Power semiconductor (switching) elements

Claims (6)

  A process of providing input / output terminals on a heat sink, a process of fixing a power semiconductor element constituting a power module (IPM) to a heat sink, a process of soldering connection, an insulating box frame having zones separated by partition walls, A step in which the heat sink or conductive plate on which the terminal connection means is formed is fixed to the heat sink with an insulation interval to connect the power semiconductor elements; a step in which each zone is filled with an insulator to complete a product intermediate; A step of performing a characteristic test of the product intermediate, a step of fixing the product intermediate to a solar cell module panel, a step of connecting and testing a solar cell module lead wire to a terminal connection means, and an insulator covering the connection portion The manufacturing method of the solar inverter mounted with IPM with an input / output terminal characterized by having the process to fill.   The heat sink having the input / output terminal connection means, to which the power semiconductor element is fixed, is connected to the heat sink and the conductive plate fixed to the insulator with an insulation interval, and is filled with the insulator. A power module (IPM) is constituted by the insulating box frame, is fixed to the solar cell module panel, the solar cell module output line is connected to the terminal connection means, and a portion covering the connection portion is filled with an insulator. A solar inverter equipped with an IPM with input / output terminals.   The power module (IPM) is a power module (IPM) configured by a heat sink with a power element semiconductor element fixed thereto and an insulating box frame filled with an insulator and a control unit formed thereon, 3. The solar inverter equipped with an IPM and having an input / output terminal according to claim 2, wherein the power semiconductor element has a structure in which the heat resistance is improved by directly adhering to the heat sink without passing through an insulator.   4. An IPM-mounted solar inverter with input / output terminals according to claim 2, wherein the solar cell module panel has a structure fixed to a substantially central portion of the solar cell module panel via a heat conductive thin insulating plate.   5. An IPM-mounted solar inverter with input / output terminals according to claim 2, wherein the terminal connecting means formed on the heat sink is a receptacle terminal formed of a solderable metal piece.   5. An IPM-mounted solar inverter with input / output terminals according to claim 2, wherein the terminal connecting means formed on the heat sink is a receptacle terminal having a terminal structure that can be inserted and connected.

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